Abstract:
Provided are an organically modified silica master batch elastomer having superior affinity for silica and a method for preparing the same. A copolymer solution-polymerized from a conjugated diene-based monomer and a vinyl aromatic monomer is mixed in solution with organically modified silica having the silica modified with a specific aliphatic hydrocarbon to prepare the organically modified silica master batch elastomer. The organically modified silica master batch elastomer according to the present invention has improved mechanical properties, abrasion resistance and blending processability over the existing master batch elastomers containing common silica. Thus, when it is used as a tire material, improved fuel efficiency, abrasion resistance and wet traction may be expected.
Abstract:
The present invention relates to a process for polymer hydrogenation that includes: polymerizing or copolymerizing at least one conjugated diene in a hydrocarbon solvent using an organic alkali metal polymerization initiator to generate a living polymer; adding a terminating agent selected from amines, esters, ketones, or halogen compounds to deactivate the active terminal of the living polymer; and selectively hydrogenating the conjugated diene polymer using at least one organotitanium compound and a lithium hydride, which is prepared from a reactor equipped with a high-speed injection nozzle and thereby precisely controlled in regard to particle diameter. The lithium hydride as used in this process is a highly active lithium hydride having a precisely controlled particle diameter as prepared from a reactor equipped with a high-speed injection nozzle to acquire stable hydrogenation reaction rate and hydrogenation reproducibility, and particularly allow the quantitative control of the lithium hydride/titanium mole ratio in the hydrogenation of the conjugated diene polymer having different molecular weights, thereby maintaining a high hydrogenation activity.
Abstract:
This invention relates to a process for hydrogenating selectively the unsaturated double bonds of copolymer having the double bonds of conjugated diene unit, which has been widely used as a modifier of transparent impact-resistant resin or polyolefin, and polystyrene resin. According to this invention, the copolymer is saturated via hydrogenation in the presence of a novel homogeneous system organotitanium catalyst without a separate reducing agent, thus representing an extremely high hydrogenation yield with remarkable hydrogenation reproducibility. Hence, a compound represented by the following formula I is employed as an appropriate catalyst.Formula I ##STR1## Wherein Cp is a cyclopentadienyl (C.sub.5 H.sub.5) group; R.sub.1, R.sub.2 and R.sub.3 are hydrogen atom or alkyl group of 1 to 3 carbon atoms; andR.sub.1, R.sub.2 and R.sub.3 can be the same or different.
Abstract:
A method for hydrogenating living polymers that include mainly conjugated double bond monomers and aromatic vinyl monomers. At least one conjugated diene compound is polymerized or copolymerized in an inert solvent by using a polymerization initiator of organic alkali metal. The produced polymer is contacted with hydrogen in the presence of a catalyst. The catalyst is formed of a cyclopentadienyl titanium compound represented by: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are independently selected from halogen groups, C.sub.1 -C.sub.8 alkyl groups, C.sub.1 -C.sub.8 alkoxy groups, C.sub.6 -C.sub.20 aryloxy groups, C.sub.6 -C.sub.20 cycloalkyl groups, silyl groups, and carbonyl groups. A cocatalyst is provided of alkoxylithium compound represented by:R.sub.4 O--Liwherein R.sub.4 is a hydrocarbon. This cocatalyst selectively hydrogenates the unsaturated double bonds in the conjugated diene units of the living polymer.
Abstract:
There is provided a method for selectively hydrogenating a living polymer having olefinic double bonds. A monomer having at least one conjugated double bond, optionally together with an olefinic monomer, is polymerized in the presence of an alkyllithium polymerization initiator, to give a living polymer. This olefinic living polymer is reacted with a hydrocarbon compound, to give a deactivated living polymer and a hydrocarbon lithium compound. The double bonds within the conjugated dien units of the polymer are selectively hydrogenated in the presence of a monocyclopentadienyltitanium compound which is under the influence of the hydrocarbon lithium compound. The hydrocarbon, which acts as a deactivator of the living polymer, terminates the anion polymerization occurring due to an activated anion of the living polymer and thus, prevents the intermolecular cross-linking of the polymers so that the gelation of the polymers does not occur. In addition, the hydrocarbon lithium serves as a reducing agent for the hydrogenating catalyst, monocyclopentadienyltitanium compound, so that a high selectivity and hydrogenation efficiency can be obtained without accurate adjustment of Li/Ti mole ratio.
Abstract:
There are disclosed a wholly aromatic polyester represented by formula I with enhanced flame retardance and chemical stability, and a method for the preparing the same. The polymer is prepared in interface polymerization wherein an alkali aqueous phase containing cyclotriphosphagene-containing bisphenols is in contact with an organic phase containing aromatic dicarboxylic acid chlorides in the presence of a phase transfer catalyst. ##STR1## wherein m and n each are an integer which satisfies the following conditions: 0
Abstract:
The present invention relates to an organic silica master batch elastomer prepared by mixing a conjugated diene based copolymer, a vinyl aromatic copolymer or a mixture thereof prepared by solution polymerization with organically modified silica in which the surface of silica is modified with a particular organosilicon compound and a silane coupling agent in solution. The resultant organic silica master batch elastomer exhibits improved mechanical properties, wear resistance and blending processability, and can provide the effect of extending durability of a tire.
Abstract:
The present invention relates to an organic silica master batch elastomer prepared by mixing a conjugated diene based copolymer, a vinyl aromatic copolymer or a mixture thereof prepared by solution polymerization with organically modified silica in which the surface of silica is modified with a particular organosilicon compound and a silane coupling agent in solution. The resultant organic silica master batch elastomer exhibits improved mechanical properties, wear resistance and blending processability, and can provide the effect of extending durability of a tire.
Abstract:
The present invention provides a method for preparing a copolymer useful for the manufacture of tires by coupling the ends of a living polymer, obtained from copolymerization of a diene monomers in the presence of an organolithium initiator and a hydrocarbon solvent, with a multi-reactive polysiloxane compound, and then completing the reaction or subsequently modifying the remaining uncoupled ends of the polymer with an amine compound. The use of the copolymer thus obtained for tire production improves the affinity to silica and greatly enhances the dynamic properties required for tires, such as wet traction and rolling resistance.
Abstract:
A radial end-modified styrene-conjugated diene block copolymer having a general formula 1. The copolymer is obtained by synthesizing a styrene-conjugated diene block copolymer by way of copolymerization using an organic lithium initiator in the presence of a nonpolar solvent and then coupling the anionic active end of the resulting copolymer with a polyfunctional polysiloxane: (PS-PD)3Si—CH2CH2—[SiO(CH3)2—]nSi(CH3)2R Formula 1 wherein, PS is polystyrene, PD is polydiene such as polyisoprene or polyisoprene-polybutadiene, R is hydroxy group or -(PD-PS), and n is an integer of 1 to 100. The block copolymer based adhesives have low melt viscosity and excellent adhesive strength.